A lightning forecast for the London 2012 Olympics opening ceremony

Summary The UKV model provided a useful aid to forecasters and performed a good job of forecasting the location of showers around the start of the opening ceremony. When coupled with the lightning parameterisa-tions, it gave good guidance to suggest that there would be no lightning within the showers present over London and also fore-cast the signal for lightning activity to take place in the English Channel earlier that day.The information in the model rerun was passed to forecasters in the Met Office’s Operations Centre, who were able to use this when generating the forecast product for the Olympics opening ceremony. There was a light shower near the start of the opening ceremony, but the event passed off without any weather-related issues. As NWP models move towards higher horizontal-grid resolutions, they become less reliant on a parameterised convection scheme and start to resolve convection. This means that there is the potential for predict-ing lightning using NWP models themselves, rather than post-processing the model. Because of the stochastic nature of convec-tive events, the lightning forecasts are best coupled to an ensemble prediction system ning occurrence in a given region. Further research needs to be carried out to verify the forecasts over a long period and validate the parameterisations of lightning-flash rate.